Method and system for recognising a spoken identification sequence

ABSTRACT

A method for recognising a spoken identification sequence including one or more different types of identifiers, the spoken identification sequence having one of a plurality of possible predefined identifier type formats, the method including the steps of: (a) maintaining a database ( 3 ) of identification sequences having at least a first of said possible predefined identifier type formats, (b) establishing a connection between a caller ( 12 ) and a voice recognition system ( 2 ) operatively connected to the at least one database ( 3 ), (c) selecting one of said possible predefined identifier type formats, and (d) if the voice recognition system determines that the selected identifier type format corresponds to said first identifier type format providing said spoken identification sequence to the voice recognition system ( 2 ) for analysis according to the first identifier type format.

The present invention relates generally to methods and systems forrecognition of spoken identification sequences, and in particular to theidentification of spoken identification sequences having one of multiplepossible predefined formats. The present invention is suitable for usein the identification of vehicle licence number plates, and it will beconvenient to describe the invention in relation to that exemplaryapplication. It is to be appreciated, however, that the invention is notlimited to that application only.

Many institutions, such as banks and department stores, allow customersto access over a telephone network a wide variety of services. Beforethe advent of touch-tone telephones, a customer would obtain theseservices through interaction with a live customer servicesrepresentative. As touch-tone telephones became more prevalent in homes,these institutions began switching to automated customer access systems.After dialling a telephone number, a customer using such systems wouldbe asked to enter various numbers or identifiers in order to access theservices provided by those institutions.

The next generation of automated customer access systems eliminated theuse of a telephone keypad in at least part of the interaction with acaller, by the use of a speech recognition system that would prompt acaller to speak required identifiers into a telephone handset, and wouldthen analyse the spoken identification sequence to determine the servicerequested by the caller.

However, exact correspondence between a recognised identificationsequence and/an identification sequence spoken by a caller is difficultto attain. In particular, conventional telephone lines introduce signalnoise and restrictive band width limitations into the spoken voicesignal. Such a deterioration in the voice signal may cause a remotevoice recognition system to produce a recognised output that does notcorrespond to a spoken identifier. These limitations may cause the voicerecognition system to confuse similar sounding letters and numbers.Moreover, variations in the speech patterns, pronunciation andintonation of callers further limits the likelihood of successfullyrecognising identification sequence spoken by the caller.

It would therefore be desirable to provide a method and system forrecognising a spoken identification sequence that enhances thereliability and performance of existing voice recognition systems.

It would also be desirable to provide a method and system forrecognising a spoken identification sequence that has a high level ofautomation and minimises the time required to be spent with a livecustomer service representative.

It would also be desirable to provide a method and system forrecognising a spoken identification sequence that ameliorates orovercomes one or more disadvantages of known voice recognition systems.

With this in mind, one aspect of the present invention provides a methodfor recognising a spoken identification sequence including one or moredifferent types of identifiers, the spoken identification sequencehaving one of a plurality of possible predefined identifier typeformats, the method including the steps of:

(a) maintaining a database of identification sequences having at least afirst of said possible predefined identifier type formats,

(b) establishing a connection between a caller and a voice recognitionsystem operatively connected to the at least one database,

(c) selecting one of said possible predefined identifier type formats,and

(d) if the voice recognition system determines that the selectedidentifier type format corresponds to said first identifier type format,providing said spoken identification sequence to the voice recognitionsystem for analysis according to the first identifier type format.

In one embodiment of the invention, one type of identifier is a letter.Another type of identifier may be a number. In this way, the spokenidentification sequence may comprise an alpha numeric sequence ofcharacters.

In one embodiment, the identification sequence may be a vehicle licenceplate number. The predefined identifier type format may comprise acombination of a series of one or more letters and a series of one ormore numbers defining the vehicle licence plate number.

In a further embodiment, the method may include the step of the callerentering information via a telephone keypad in response to prompts forinformation from an interactive voice response system.

Another aspect of the invention provides a method for purchasing a passfor a toll road network, including the steps of:

recognising a spoken identification sequence according to theabove-described method; and

purchasing the pass for use in conjunction with a vehicle associatedwith the spoken identification sequence. The identification sequence maycorrespond to a vehicle licence plate number.

Another aspect of the invention provides a method for recognising aspoken identification sequence including one or more different types ofidentifiers, the spoken identification sequence having one of aplurality of possible predefined identifier type formats, the methodincluding the steps of:

(a) maintaining at least one database of identification sequences havingat least a first of said possible predefined identifier type formats,

(b) selecting one of said possible predefined identifier type formats,

(c) determining that the selected identifier type format corresponds toone of the predefined identifier type formats, said determination beingperformed by a voice recognition system, and

(d) if the voice recognition system determines that the selectedidentifier type format corresponds to one of said predefined identifiertype formats, providing said spoken identification sequence to the voicerecognition system for analysis according to the predefined identifiertype format.

The identification sequence may be a vehicle licence plate number. Thusa user, by enunciating a vehicle licence plate number as an identifiermay, at the option of providing a password or other user identifier,obtain access to a further database that contains details of multipleregistered licence plate numbers. Furthermore, the user may have accessthrough this user identifier to details of one or more accountsmaintained for each registered licence plate number, and may optionallymodify selected accounts and/or registered licence plate numbers.

Alternatively the user, who may be a caller, can establish a connectionto a voice recognition system connected to the at least one database andprovide a spoken identification sequence which is recognised ascorresponding to one of the predefined identifier type formats. In thisway, any vehicle licence plate number, for example, can be spoken andrecognised by the system.

A further aspect of the invention provides an information processingsystem for recognising a spoken identification sequence including one ormore different types of identifier. The spoken identification sequencehaving one of a plurality of possible predefined identifier typeformats, the system including at least one database of identificationsequences having at least a first of said possible predefined identifiertype formats, and a voice recognition system operatively connected tothe at least one database and including a processing unit and associatedmemory means for storing computer program code for causing theprocessing unit to perform the steps of:

receiving one of said possible predefined identifier type formatsselected by a caller, and

if the voice recognition system determines that the selected identifiertype format corresponds to said first identifier type format, analysingsaid spoken identification sequence provided to the voice recognitionsystem by the caller according to the first identifier type format.

Yet another aspect of the invention provides a voice recognition systemforming part of the above described information processing system.

A further aspect of the invention provides a computer program includingcomputer program code for use in conjunction with the above-describedvoice recognition system, the computer program code causing the abovedescribed processing unit to perform the above-mentioned steps.

The following description refers in more detail to the various featuresof the method and system for recognising a spoken identificationsequence of the present invention. To facilitate an understanding of theinvention, reference is made in the description to the accompanyingdrawings where the method and system for recognising a spokenidentification sequence are illustrated in a preferred embodiment. It isto be understood however that the invention is not limited to thepreferred embodiment as illustrated in the drawings.

In the drawings:

FIG. 1 is a schematic diagram illustrating one embodiment of aninformation processing system according to the present invention;

FIG. 2(a) is a flow chart illustrating the functional steps performed bythe information processing system of FIG. 1 using speech recognition andinteractive voice responses;

FIG. 2(b) is a flow chart illustrating the functional steps performed bythe information processing system of FIG. 1 using a combination oftelephone keypad input by a caller, speech recognition and interactivevoice responses; and

FIGS. 3 to 6 are flow charts illustrating the functional steps performedby the information processing system of FIG. 1 in the recognition of aspoken vehicle licence plate number forming part of the function stepsdepicted in FIG. 2.

Referring now to FIG. 1, there is shown generally an informationprocessing system 1 including a voice recognition system 2, database 3,telephony switch 4, call centre 5 and computer/telephony integrationsystem 6. The voice recognition system includes an interactive voiceresponse system 7, a multi function speech processing platform 8, anecho canceller 9 and a transaction processing server 10. Atelecommunications network 11 enables a caller 12 to establish aconnection and interact with the information processing system 1.

In use, the caller 12 initially establishes a connection with thetelephony switch 4 via the telecommunications network 11. The call isinitially directed to the echo canceller 9 to eliminate or reduce theeffect of an echo in the speech signal from the caller 12. The speechsignal is then provided to the input of the interactive voice responsesystem 7. A natural speech recognition application enables theinteractive voice response system 7 to accept and interpret naturallanguage speech input from the caller 12. The interactive voice responsesystem 7 provides an output to the caller 12 in the form of prerecordedmessages or computer generated speech, and accepts and interprets voiceresponse inputs from the caller 12.

Processing of the speech signal from the caller 12 in response to thevarious prompts provided by the interactive voice response system 7 areprocessed and analysed by the multi function speech processing platform8. The analogue speech signals provided at the input of the multifunction speech processing platform 8 are converted into digital signalscorresponding to predefined alpha numeric or other identifierscorresponding to a caller spoken signal. The interactive voice responsesystem 7 provides an output to the telephony switch 4 in order toselectively divert calls from the caller 12 to the call centre 5 andhandling by a live customer services representative.

The database 3 stores identification sequences of alpha numeric or otheridentifiers, such as vehicle licence plate numbers. The transactionprocessing server 10 acts to match a spoken identification sequenceprovided by a caller 12 with an identification sequence maintained inthe database 3.

The computer/telephony integration system 6 acts to receive informationcaptured by the interactive voice response system 7 and the transactionprocessing server 10 during interactions with the caller 12, and toprovide this captured information as required to a customer servicesrepresentative during a direct interaction with a caller 12.

The interactive voice response system 7, multi function speechprocessing platform 8 and transaction processing server 10 each includea processing unit and associated memory means for storing computerprogram code to cause each of these elements to perform thefunctionality illustrated in FIGS. 2(a), 2(b) and FIGS. 3 to 6. Inparticular, FIGS. 2(a), (2(b) illustrates a method for enabling thecaller 12 to purchase a pass for a toll road network using theinformation processing system 1 shown in FIG. 1.

Initially, the caller 12 establishes a connection with the informationprocessing system 1 by dialling in through the telecommunicationsnetwork 11 and telephony switch 4. Upon establishment of the connection,the interactive voice response system 7 provides a computerised welcomemessage, at step 20 in FIG. 2(a), to the telephony switch 4 fortransmission to the caller 12. At step 21, the user is prompted toprovide the intended date on which they will be using the toll roadnetwork in question. Upon receipt of that date information, the caller12 is then prompted to provide the class of the vehicle for which thepass is to be issued. At step 23, the caller is prompted to provide themake and model of the vehicle for which the pass is to be issued, and atstep 24 whether the pass is to be for a predetermined period of time orfor a predetermined portion of the toll road network only.

Having successfully provided the information at steps 21 to 24 requiredfor a pass to be purchased, the interactive voice response system 7provides computer generated speech to the telephony switch 4 fortransmission to the caller 12 detailing the terms and conditions of thepass to be purchases. The information provided in steps 21 to 25 may beentered by the user either by conventional touch-tone data entry, or bysimple interactions. with the interactive voice response systems 7. Manyof these interactions require either a “yes” or “no” response from thecaller 12, or require the caller 12 to provide one of a limited numberof spoken word responses that are relatively easily distinguishable bythe multi function speech processing platform 8.

At step 26, the caller 12 is prompted by the interactive voice responsesystem 7 to provide the licence plate number of the vehicle for whichthe pass is to be purchased. Unlike the information provided by thecaller 12 in response to prompts from the interactive voice responsesystem 7 in steps 21 to 25, a vehicle licence plate number spoken by thecaller 12 may be a numeric sequence of variable length, a sequence ofletters of variable length, or both combined in a alpha numericsequence. The number and position of each alpha numeric identifier inthe licence plate number may also vary, as may the number of identifiersused in each vehicle licence plate number. Accordingly, the recognitionof a spoken identification sequence corresponding to a vehicle licenceplate number is difficult, and results in high error rates in knownsystems.

However, according to the present invention, prior to an analysis of aspoken identification sequence by the multi function speech processingplatform 8, pre filtering of the vehicle licence plate number occurs.The possible predefined identifier type formats of various types ofvehicle licence plate numbers that may be required to be recognised bythe information processing system 2 are stored in the interactive voiceresponse system 7. For example, a first type of vehicle licence platenumber may have a predefined identifier type format consisting of aseries of three letters followed by a series of three numbers. Otherpredefined identifier type formats may consist of one or more series ofletters and/or numbers of differing lengths and positions.

By prompting the caller 12 to identify the predefined identifier typeformat in which the vehicle licence plate number is subsequently to bespoken, the task of recognising the vehicle licence plate number fromthe identification sequence spoken by the caller 12 is greatlyfacilitated.

Accordingly, at step 40, in FIG. 3 the interactive voice response system7 provides a computerised speech signal to the caller 12 asking, in thisexample, whether the vehicle for which the pass is to be issued has avehicle licence plate number in a standard format of three lettersfollowed by three numbers. Upon receiving the response from the caller12 at step 41, and analysis of the “yes” or “no” response at step 42,the user is requested to spell the licence plate number (see FIG. 4), oralternatively this step is bi passed and a subsequent step in theprocess illustrated in FIG. 2(a), such as the entry of credit carddetails at step 27 is performed. The user is then able to purchase apass for use in conjunction with a vehicle associated with the vehiclelicence plate number (or other spoken identification sequence). Thevehicle licence plate number may be provided to a customer servicerepresentative at the call centre 5 once information has been collectedby the interactive voice response system 7 in relation to the othersteps shown in FIG. 2.

At step 50 in FIG. 4, the caller 12 is prompted by the interactive voiceresponse system 7 to speak the vehicle licence plate number. At step 51the spoken identification sequence is provided by the caller 12, andanalysed by the multi function speech processing platform 8 at step 52.In so doing, the spoken identification sequence provided by the caller12 to the voice recognition system 2 is analysed according to theidentifier type format indicated by the caller 12 in the responseprovided at step 41. If it is determined at step 53 that a valid licenceplate number has not been provided, an error handling procedure isenabled at step 54. Otherwise, further processing of the request for apass to the toll road network takes place.

At step 55, a data field recording the number of passes that have beenissued to the caller 12 within a previous twelve month period isaccessed. At step 56, a determination is made as to whether more than apredetermined number of passes have been issued during that period. Ifthis is the case, the interactive voice response system 7 plays acomputerised speech message to the caller 12 that that predefined limithas been exceeded, and information captured by the interactive voiceresponse system 7 from the caller 12 is transferred to a customerservice representative at the call centre 5 for further handling of thecall, at step 58. If the number of passes issued to the caller 12 withinthe preceding twelve months has not exceeded a predefined limit, anassessment may be made at step 59 as to the degree of confidence in therecognition of the spoken identification sequence from the caller 12.Upon determination that the vehicle licence plate number has beenidentified with a high degree of confidence, payment for the toll roadnetwork pass may be initiated at step 60. Otherwise, the call, togetherwith information captured by the interactive voice response system 7,may be transferred to a customer service representative of the callcentre 5.

FIG. 2(b) shows an alternative process to that shown in FIG. 2(a) forpurchasing a pass for a toll road network, using the informationprocessing system 1 shown in FIG. 1. Again initially the caller 12establishes a connection with the information processing system 1 bydialling on their telephone terminal using the telecommunicationsnetwork 11 and telephony switch 4. Steps 100 through to 114 may beprocessed via telephone touch-tone data entry by the caller andinteractive voice responses from the system 1. Thus at step 100, uponestablishment of the connection the interactive voice response system 7provides a computerised welcome message for transmission to the caller.At step 102 the user is prompted to enter the intended date of travelover the toll road network. Upon receipt of that date information, thecaller 12, is then prompted to enter into their telephone terminal theclass of the vehicle for which the pass is to be issued at step 104.

At step 106 the type of pass is prompted by the interactive voiceresponse system 7 for entry by the caller, whether this is for apredetermined period of time or for a predetermined portion of the tollroad network only. The terms and conditions of the pass to be purchasedis recited back to the caller at step 108 whereby the system 7 providescomputer generated speech to the telephony switch 4 for transmission tothe caller 12. At step 110 the caller is then prompted by the system 7to enter their credit card number and expiry details. At step 112 thecaller is given the option of bypassing steps 116 to 124 which wherebynatural language speech input from the caller is accepted andinterpreted by the voice response system 7 in accordance with theprocesses undertaken with respect to FIG. 2(a). The caller has theoption to be transferred to a customer representative at step 114 tocontinue to complete the process for obtaining a pass for the toll roadnetwork.

At step 116 the caller is prompted to provide the make and model of thevehicle for which the pass is to be issued, which is similar to step 23in FIG. 2(a). At step 118 the caller is prompted to provide the licenceplate number of the vehicle, similar to step 26 in FIG. 2(a) and thenconfirm the details at step 120. The payment is then processed by thesystem 1 at step 122 and at step 124 the process is complete.

In an alternative embodiment, confirmation of the vehicle licence platenumber may be requested. As seen in FIG. 5, an assessment may be made atstep 70 as to whether this is the first confirmation to be performed. Ifso, the vehicle licence plate number recognised by the interactive voiceresponse system 7 is played back to the caller 12 at step 71. A responseas to whether this is the correct vehicle licence plate number is thenprovided by caller 12 at step 72, and interpreted at step 73 by themulti function speech processing platform 8. If the caller 12 confirmsthat the correct vehicle licence plate number had been interpreted, amessage of thanks is played to the caller at step 74 and theidentification of a credit card information for payment of the pass atstep 27 proceeded with. Alternatively, a message requesting the caller12 to repeat the vehicle licence plate number is played to the caller 12at step 75, and a second attempt at confirmation occurs.

As seen in FIG. 6, the interactive voice response system 7 determines atstep 80 whether this is the second confirmation attempt. If the secondconfirmation attempt has already been attempted unsuccessfully, amessage is played at step 81 to the caller 12 indicating thatidentification of the vehicle licence plate number has beenunsuccessful. At step 82, a further message is played to the caller 12by the interactive voice response system 7, indicating that credit carddetails will subsequently be obtained from the caller 12, prior to thecall being transferred to a customer service representative from thecall centre 5 in order to obtain the vehicle licence plate number from alive interaction with that customer service representative.

Alternatively, if at step 80 was determined that this was the secondattempt at confirmation, the voice response provided by the caller 12 isanalysed, and replayed to the caller 12 at step 83. A voice inputprovided by the caller 12 at step 84 is then analysed at step 86 todetermine whether the caller 12 has confirmed correct recognition of thevehicle licence plate number. If the caller 12 has indicated “yes”, amessage of thanks is played to the user at step 86. If the caller 12 hasindicated “no”, a further message is played to the user at step 87requesting that the user repeat the vehicle licence plate number.Recognition of the vehicle licence plate number is then re attempted atstep 88.

Finally, it is to be understood that various modifications and/oradditions may be made to the method and system for recognising a spokenidentification sequence without departing from the spirit or ambit ofthe present invention as defined hereabove.

1. A method for recognising a spoken identification sequence includingone or more different types of identifiers, the spoken identificationsequence having one of a plurality of possible predefined identifiertype formats, the method including the steps of: (a) maintaining adatabase of identification sequences having at least a first of saidpossible predefined identifier type formats; (b) establishing aconnection between a caller and a voice recognition system operativelyconnected to the at least one database; (c) selecting one of saidpossible predefined identifier type formats and (d) if the voicerecognition system determines that the selected identifier type formatcorresponds to said first identifier type format, providing said spokenidentification sequence to the voice recognition system for analysisaccording to the first identifier type format.
 2. A method according toclaim 1, wherein one type of identifier is a letter.
 3. A methodaccording to claim 2, wherein another type of identifier is a number. 4.A method according to claim 2, wherein the spoken identificationsequence comprises an alpha numeric sequence of characters.
 5. A methodaccording to claim 1, wherein the identification sequence is a vehiclelicence plate number.
 6. A method according to claim 5, wherein thepredefined identifier type formal comprises a combination of a series ofone or more letters and a series of one or more numbers defining thevehicle licence plate number.
 7. A method according to claim 1, themethod further including the step of: the caller entering informationvia a telephone keypad in response to prompts for information from aninteractive voice response system.
 8. A method for purchasing a pass fora toll road network, including the steps of: recognizing a spokenidentification sequence; and purchasing the pass for use in conjunctionwith a vehicle associated with the spoken identification sequence.
 9. Amethod for recognising a spoken identification sequence including one ormore different types of identifiers, the spoke identification sequencehaving one of a plurality of possible predefined identifier typeformats, the method including the steps of: (a) maintaining at least onedatabase of identification sequences having at least a first of saidpossible predefined identifier type formats; (b) selecting one of saidpossible predefined identifier type formats; (c) determining that theselected identifier type format corresponds to one of the predefinedidentifier type formats, said determination being preformed by a voicerecognition system; and (d) if the voice recognition system determinesthat the selected identifier type format corresponds to one of saidpredefined identifier type formats, providing said spoken identificationsequence to the voice recognition system for analysis according to thepredefined identifier type format.
 10. A method according to claim 9,wherein the identification sequence is a vehicle licence plate number.11. A method according to claim 10, the method further including:providing user access to a further database containing details ofmultiple registered licence plate numbers.
 12. A method according toclaim 11, wherein user access to said further database is facilitatedupon providing a user identifier.
 13. A method according to claim 11,the method further including: providing user access to one or moreaccounts maintained for each registered licence plate number.
 14. Amethod according to claim 13, the method further including: enablinguser modification of selected accounts and/or registered licence platenumbers.
 15. A method according to claim 9, the method furtherincluding: the user establishing a connection to a voice recognitionsystem connected to the at least one database, and providing a spokenidentification sequence which is recognised as corresponding to one ofthe predefined identifier type formats.
 16. An information processingsystem for recognising a spoken identification sequence including one ormore different types of identifier, the spoken identification sequencehaving one of a plurality of possible predefined identifier typeformats, the system including: at least one database of identificationsequences having at least a first of said possible predefined identifiertype formats; and a voice recognition system operatively connected tothe at least one database and including a processing unit and associatedmemory means for storing computer program code for causing theprocessing unit to perform the steps of: receiving one of said possiblepredefined identifier type formats selected by a caller; and if thevoice recognition system determines that the selected identifier typeformat corresponds to said first identifier type format, analysing saidspoken identification sequence provided to the voice recognition systemby the caller according to the first identifier type format.
 17. A voicerecognition system forming part of an information processing system forrecognising a spoken identification sequence including one or moredifferent types of identifier, the spoken identification sequence havingone of a plurality of possible predefined identifier type formats, thesystem including: at least one database of identification sequenceshaving at least a first of said possible predefined identifier typeformats; and wherein the voice recognition system is operativelyconnectable to the at least one database and includes a processing unitand associated memory means for storing computer program code forcausing the processing unit to perform the steps of: receiving one ofsaid possible predefined identifier type formats selected by a caller;and if the voice recognition system determines that the selectedidentifier type format corresponds to said first identifier type format,analysing said spoken identification sequence provided to the voicerecognition system by the caller according to the first identifier typeformat.
 18. The voice recognition system of claim 17 further comprisinga computer program including computer program code, the computer programcode causing the processing unit to perform the steps of receiving oneof said possible predefined identifier type formats selected by a callerand analyzing said spoken identification sequence provided to the voicerecognition system by the caller according to the first identifier typeformat.